Telephone transmission system



Oct 30, 19253.

. H. BENIDERNAGEL TELEPHONE TRANSMISSION SYSTEM Filed Dec. 6, 1919 Smarts-Sheet ll .EFIr :2 1

Oct. 30, 1923. fififififi? W. H. BENRDERNAGEL TELEPHONE TRANSMISSION SYSTEM Filed Dec. 6, 1919 2 Shemaks-Sheet 2 //7 [ken/6%:

WILLIAM H. BENDERNAGEL, OF QUEENS, YORK, .ttS-dIGi-tl'fllt TO WESTERN EIIEG- CUBIC COMPANY, INCQRPORA'IED, OF NEW YORK, 1V. TEX, A. CORPORATION 035 NEW TELEPHONE TRANSllTIfi-SIQN STiTfiTE-ltt.

Application filed December 6, 1919.

To all whom it may concern Be it known that I, VVILLIAlii H. BENDER- NAGEL, a citizen out the United States, residing at Queens, in the county of Queens, State of New York, have invented certain new and useful Improvements in Telephone Transmission Systems, of which th following is a full, clear, concise, and exact description.

This invention relates to telephone transmission systems and more particularly to such circuits in which repeaters are employed. The object of the invention is to provide an amplifying repeater in a subscribers telephone line circuit.

One of the features of the invention is the provision of means for causing the operation of a cut-ofif' relay to disconnect the line relay from the line and simultaneously to connect battery to the filament of the re peater to render the same operative. Another feature is to render the repeater operative when the operator answers a subscribers call. Another feature is to connect the subscribers line with a relay for controlling; the supervisory signal of the connected cord or link circuit.

Other features and advantages of the invention will be obvious as the description proceeds. The invention will be readily und'erst-ood from the description in connection with the drawings in which three embodiments of the invention are illustrated.

In the drawings:

1 shows a line circuit in which a single oneway amplifier employed and in which provision is made for ringing from a switchboard through the hybrid coils asso' ciated with the amplifier.

Fig. 2 shows a line circuit equipped with a single one-way amplifier provided with an apparatus whereby when an operator rings a subscriber, the amplifier is disconnected and the ringing current pa. directly through to the subscribers station.

Fig. 3 is similar to Fig. 2,, except that the subscribers line circuit is equipped with two one-way repeaters.

In each of the en'ibodiments oi the invention is shown means by which the subscriber can flash. a signal lamp to call the operato whether the plug is in the subscribers ask or not and also for permitting the operator to ring the subscriber as is common.

I The invention will be particularly de- Serial lilo. 343,011..

scribed in connection with l ig. 1 and will be more briefly described in connection with the other figures. In Fig. 1 at A. is indicated subscribers telephone set of the usual construction, having the primary of a transformer 6 in circuit therewith. The subscribers line circuit extends through. the transformer 6 and connections, which will be described below in detail, to jack J at the central station.

W hen the subscriber A. removes his receiver, a circuit is closed from ground through battery and relay 1, primary of transformer 6., subscribers transmittenbaclz to ground. The consequent energization of relay 1 causes the lighting of the line lamp 2, over an obvious circuit. 'lhereupon the operator inserts the plug P of the cord circuit into the jack J, thereby closing a circuit from ground through the battery and lamp d sleeve contacts of plug P and jack d, through relay 3 to ground. ldelay 3 bccomes energized, and at its left-hand back contacts cuts off the line relay 1 which releases and thus extinguishes the line lamp 2. The right-hand forward contact of rela 3, is also closed by the energization of said relay. The relay 3 closes at its left-hand forward contacts a circuit from ground and bat tery through relay 5 and the subscribers set back to ground. The energization of relay 5 closes a circuit from ground and battery through the forward contact of relay 5 and through relay 3 to ground, thereby shunting and extinguishing the supervisory lamp The closing 01? the right-hand contact of relay 3 supplies heating current to the filament of the bulb lit to ground.

The apparatus is now in condition for amplifying outgoing currents from the subscriber A. as follows: Transmission. currents from subscriber A pass throur h the primary oi transformer 6 where it ransformed through the secondary oit transiifornr or 6 and circulates in the circuit comprising the secondary of transformer 6 and the neutralizingr balancing network hi and the primary of transformer 'i. T he ltralancer hi maintains the points 8 and 8" at equal ootentia-is, so that none of the current through the primary ct transformer 8. The current passing through the primary oi transformer 7 is transformed to the sec ondary from whence it passes through the input side of repeater R, where it is ampliiii lllti fied and passes to the points 7, 7, thence through the jack J and plug Pto the cord circuit.

Eitherringing or talking current passes from the cordcircuit 'throughthe plug and jack to the subscriber A without being amplified as follows: from jack J through the circuit comprising the neutralizing balancing network N and the-primary. of transformer 8. The points 7', '7 being maintained at the same potentials by the balancer N, nocurrentpassesto the repeater R, but is transformed to the secondary of transformer 8 from which it passes to the points 8', 8", thence through the transformer 6 to the subscriber A.

When the plugPis-in the jack J, the subscriber A can flash the supervisory signal light 4 by moving his hook up and down. This operation is possible because the succes sive opening and closing of the circuit through the subscribersset energizes and deenergizesrthe relay 5, thereby vibrating its armature to open and close the circuit from I ground through contact of relay 5 and the relay 3. It'is thus seen that the subscriber A may signal the operatorwhen the plugP s in the jack J through the supervisory lamp 4, and may signal her through the line lamp 2 when the plug is out of the jack.

Withdrawal of the plug P from jack J before the subscriber hangs up his receiver doesnot render the repeater inoperative because even with the plug out, current continues-through relay 3 from contact of relay 5, thus maintaining the filament of the repeater; active until the subscriber hangs up. Likewise hanging up of the subscribers receiver'while plug B is in jack J will not cut Ofi 1tl18'Cl1II'811t: from the filament, since current is maintained from battery through lamp 4, sleeve contacts of plug and jack, through relay 3 to. ground.

In Fig. 2 parts similar to those shown in Fig. 1 are designated by similar reference figures, except that the subscript 2' is used. The operation of identical parts in the two figures are exactly alike so it is deemed unnecessary to describe the same in detail in connection with this figure. In addition to the apparatus of Fig. 1, the embodiment shown in Fig. 2 is provided with the relay t), and the relays 10 10",, together with the connecting lines 11,. When alternating or pulsating ringing current comes through jack J relay 9 is energized, thereby per mitting current to flow from ground and battery, through relays 10,, 1O in parallel and contact of relay 9 to ground, thus-closing the inner, upper and lower contacts of relays 10 10 and cuttingoff the repeater and amoeiated parts,- so that ringing current goes, directly to the bell of subscriber a hrough e 12 r mjackJ In Fig. 3, parts si nilar to those shown in rigs. 1 and it are designated by similar refence characters, except that the subscript 3 is used. The operation of identical parts in Fig. 3 is exactly the same as in Fig. 2, so it is deemed unnecessary lo explain the same in detail. In addition. the cnibmlimcnt shown in Fig. 3 is ')ro\'ided with another rcpeaterlt' so that both the ontgoiu and the incoming talking current is amplified. The amplification of the outgoing talking current has already been explained in connection with Fig. l. The incoming talking current passes through ring and tip contacts of jack J and through the circuit comprising the neutralizingbalancing network N and the primary of transformer 8 where it is transformed to the secondary of transformer 8,, passes through the input circuit of repeater R where it is an)- plified and passes through the output circuit of the same to the points 8' and 8, and then through the transformer 6 to the subscribers set A The points 7 7",, :1 nd 8' and 8", are maintained at equal potentials by the balancers N, and N respectively, so that outgoing talking current is forced to pass through repeater R and incoming talking current is forced to pass through R,.

hat is claimed is:

1. In a telephone system, a subscribers line terminating at a central switchboard, a link circuit, an amplifying repeater in said line, and means for causing ringing current to cut out said repeater and connect said link circuit directly to said subscribers bell.

2. In a telephone system, a subscribers line terminating at a central switchboard, a link circuit, an amplifying repeater in said line, and a relay operable by ringing current to alter connections so as to cut out said repeater and establish direct connection from said link circuit to said subscribers bell durin the application of ringing current.

3. In a telephone system a subscribers line terminating at a central switchboard, repeater in said line, a link circuit, and means for rendering said repeater operative upon connecting said link circuit to said line, and means for cutting out said repeater and establishing direct connection between said link circuit and the subscribers hell by ringing current from said link circuit.

4:. In a telephone system, a subscribcrs line terminating at a central switchboard. a repeater in said line, a link circuit, and means for rendering said repeater operative upon connecting said link circuit to said line,- and a relay operable by ringing current to alter connections so as to cut out said repeater and establish direct connection from said link circuit to said subscribers bell during the application of ringing current.

5. In a, telephone system, a subscribers line including a line relay and cut oif relay associated with said line; a link circuit; an. amplifier in said. subscribers line; a supervisory signal; a relay for controlling said signal; and means whereby operation of said cut oil relay disconnectsthe line relay from the line, renders the repeater operative, and connects the supervisory relay with said subscribers line.

(5. A local. subscribers line terminating at one end at a central switchboard, a local subscribers substation set at the other end of said line, a vacuum tube in said line, and m ansdirectly controlled by the operation of connections at said set for controlling said tube independently of voice currents in said line.

7. In combination, a line section, a second line section, a balancing artificial line for each of said lines, a three-winding transformer having one winding in said first line section and a second winding in the corresponding artificial line, a second threewinding transformer having a winding in said second line section and a second winding in the corresponding artificial line, connections betwen the third winding of said first transformer and midpoints of the two mentioned windings of said second transformer, connections between the third windin of said second transformer and the midpoints of the two first-mentioned windings of said first transformer, and an amplifying repeater in only one of said connections.

8. In an electric system, a local subscribers line terminating at one end in a local subscribers substation set and at the other end terminating in a central office at which a plurality of lines terminate, a link circuit at said central office adapted to interconnect said first line with another line, a normally inoperative amplifying repeater in said first line, means controlled by the connection of said link circuit to said first local line for rendering said repeater operative, and for maintaining said repeater operative even after said link circuit is disconnected from said line, and means controlled by the disconnection of an element of said subscribers set from said first line for rendering said repeater inoperative.

9. In an electric system, a local subscribers line terminating at one end in a local subscribers substation set and at the other end terminating in a central. ofiice at which a plurality of lines terminate, a link circuit at said central office adapted to interconnect said first line with another line, a normally inoperative amplifying repeater in said first line, means controlled by the connection of said link circuit to said first line for rendering said repeater operative, and means responsive to the disconnection of the receiver of said subscribers set from said first line for rendering said repeater inoperative after said link circuit has been disconnected from said first line.

10. In an electric system, a local subscribers line terminating at one end in a local subscribers substation set and terminating at the other end in a central switchboard, a link circuit adapted to be connected to the switchboard end of said line, a normally inoperative repeater in said line, a supervisory relay, a supervisory signal controlled by said relay, a cut-off relay controlled by the con nection of said link circuit to said line, and connections whereby the operation of said cut-off relay renders said repeater operative and places said supervisory relay under the control of said subscribers line.

11. In an electric system, a local subscribers line terminating at one end in a local subscribers substation set and terminating at the other end in a central switchboard, a link circuit adapted to be connected to the switch board end of said line, an amplifying repeater between. said set and said link circuit, a line relay responsive to a signal from said subscribers set, signaling means controlled by said relay, a supervisory signal, and means controlled by the connection of said link circuit to said local line for rendering said repeater operative, for disconnecting said line relay from said line, and for placing said supervisory signal under the control of said subscribers set.

12. In an electric system, a local subscribers line terminating at one end in a local subscribers substation set and terminating at the other end in a central switchboard, a link circuit adapted to be connected to the switchboard end of said local line, a normally inoperative amplifying repeater in said local line, a line relay controlled by a signal from said subscribers set, signaling means controlled by said line relay, a supervisory relay, a supervisory signal controlled by said supervisory relay, and a cut-off relay controlled by the connection of said link circuit to said local line for rendering said repeater operative, for disconnecting said! line relay from said line, and for placing said supervisory relay under the control of said local subscribers set.

In witness whereof, I hereunto subscribe my name this 3rd day of December, A. D. 1919.

WILLIAM BENDERNAGEL. 

